/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * This RCM module adds support to the RCM framework for VLAN links
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <synch.h>
#include <assert.h>
#include <strings.h>
#include "rcm_module.h"
#include <libintl.h>
#include <libdllink.h>
#include <libdlvlan.h>
#include <libdlpi.h>

/*
 * Definitions
 */
#ifndef lint
#define _(x)    gettext(x)
#else
#define _(x)    x
#endif

/* Some generic well-knowns and defaults used in this module */
#define RCM_LINK_PREFIX         "SUNW_datalink" /* RCM datalink name prefix */
#define RCM_LINK_RESOURCE_MAX   (13 + LINKID_STR_WIDTH)

/* VLAN link flags */
typedef enum {
        VLAN_OFFLINED           = 0x1,
        VLAN_CONSUMER_OFFLINED  = 0x2,
        VLAN_STALE              = 0x4
} vlan_flag_t;

/* link representation */
typedef struct dl_vlan {
        struct dl_vlan  *dv_next;               /* next VLAN on the same link */
        struct dl_vlan  *dv_prev;               /* prev VLAN on the same link */
        datalink_id_t   dv_vlanid;
        vlan_flag_t     dv_flags;               /* VLAN link flags */
} dl_vlan_t;

/* VLAN Cache state flags */
typedef enum {
        CACHE_NODE_STALE        = 0x1,          /* stale cached data */
        CACHE_NODE_NEW          = 0x2,          /* new cached nodes */
        CACHE_NODE_OFFLINED     = 0x4           /* nodes offlined */
} cache_node_state_t;

/* Network Cache lookup options */
#define CACHE_NO_REFRESH        0x1             /* cache refresh not needed */
#define CACHE_REFRESH           0x2             /* refresh cache */

/* Cache element */
typedef struct link_cache {
        struct link_cache       *vc_next;       /* next cached resource */
        struct link_cache       *vc_prev;       /* prev cached resource */
        char                    *vc_resource;   /* resource name */
        datalink_id_t           vc_linkid;      /* linkid */
        dl_vlan_t               *vc_vlan;       /* VLAN list on this link */
        cache_node_state_t      vc_state;       /* cache state flags */
} link_cache_t;

/*
 * Global cache for network VLANs
 */
static link_cache_t     cache_head;
static link_cache_t     cache_tail;
static mutex_t          cache_lock;
static int              events_registered = 0;

static dladm_handle_t   dld_handle = NULL;

/*
 * RCM module interface prototypes
 */
static int              vlan_register(rcm_handle_t *);
static int              vlan_unregister(rcm_handle_t *);
static int              vlan_get_info(rcm_handle_t *, char *, id_t, uint_t,
                            char **, char **, nvlist_t *, rcm_info_t **);
static int              vlan_suspend(rcm_handle_t *, char *, id_t,
                            timespec_t *, uint_t, char **, rcm_info_t **);
static int              vlan_resume(rcm_handle_t *, char *, id_t, uint_t,
                            char **, rcm_info_t **);
static int              vlan_offline(rcm_handle_t *, char *, id_t, uint_t,
                            char **, rcm_info_t **);
static int              vlan_undo_offline(rcm_handle_t *, char *, id_t, uint_t,
                            char **, rcm_info_t **);
static int              vlan_remove(rcm_handle_t *, char *, id_t, uint_t,
                            char **, rcm_info_t **);
static int              vlan_notify_event(rcm_handle_t *, char *, id_t, uint_t,
                            char **, nvlist_t *, rcm_info_t **);
static int              vlan_configure(rcm_handle_t *, datalink_id_t);

/* Module private routines */
static void             cache_free();
static int              cache_update(rcm_handle_t *);
static void             cache_remove(link_cache_t *);
static void             node_free(link_cache_t *);
static void             cache_insert(link_cache_t *);
static link_cache_t     *cache_lookup(rcm_handle_t *, char *, char);
static int              vlan_consumer_offline(rcm_handle_t *, link_cache_t *,
                            char **, uint_t, rcm_info_t **);
static void             vlan_consumer_online(rcm_handle_t *, link_cache_t *,
                            char **, uint_t, rcm_info_t **);
static int              vlan_offline_vlan(link_cache_t *, uint32_t,
                            cache_node_state_t);
static void             vlan_online_vlan(link_cache_t *);
static char             *vlan_usage(link_cache_t *);
static void             vlan_log_err(datalink_id_t, char **, char *);
static int              vlan_consumer_notify(rcm_handle_t *, datalink_id_t,
                            char **, uint_t, rcm_info_t **);

/* Module-Private data */
static struct rcm_mod_ops vlan_ops =
{
        RCM_MOD_OPS_VERSION,
        vlan_register,
        vlan_unregister,
        vlan_get_info,
        vlan_suspend,
        vlan_resume,
        vlan_offline,
        vlan_undo_offline,
        vlan_remove,
        NULL,
        NULL,
        vlan_notify_event
};

/*
 * rcm_mod_init() - Update registrations, and return the ops structure.
 */
struct rcm_mod_ops *
rcm_mod_init(void)
{
        dladm_status_t status;
        char errmsg[DLADM_STRSIZE];

        rcm_log_message(RCM_TRACE1, "VLAN: mod_init\n");

        cache_head.vc_next = &cache_tail;
        cache_head.vc_prev = NULL;
        cache_tail.vc_prev = &cache_head;
        cache_tail.vc_next = NULL;
        (void) mutex_init(&cache_lock, 0, NULL);

        if ((status = dladm_open(&dld_handle)) != DLADM_STATUS_OK) {
                rcm_log_message(RCM_WARNING,
                    "VLAN: mod_init failed: cannot open datalink handle: %s\n",
                    dladm_status2str(status, errmsg));
                return (NULL);
        }

        /* Return the ops vectors */
        return (&vlan_ops);
}

/*
 * rcm_mod_info() - Return a string describing this module.
 */
const char *
rcm_mod_info(void)
{
        rcm_log_message(RCM_TRACE1, "VLAN: mod_info\n");

        return ("VLAN module version 1.2");
}

/*
 * rcm_mod_fini() - Destroy the network VLAN cache.
 */
int
rcm_mod_fini(void)
{
        rcm_log_message(RCM_TRACE1, "VLAN: mod_fini\n");

        /*
         * Note that vlan_unregister() does not seem to be called anywhere,
         * therefore we free the cache nodes here. In theory we should call
         * rcm_register_interest() for each node before we free it, the
         * framework does not provide the rcm_handle to allow us to do so.
         */
        cache_free();
        (void) mutex_destroy(&cache_lock);

        dladm_close(dld_handle);
        return (RCM_SUCCESS);
}

/*
 * vlan_register() - Make sure the cache is properly sync'ed, and its
 *               registrations are in order.
 */
static int
vlan_register(rcm_handle_t *hd)
{
        rcm_log_message(RCM_TRACE1, "VLAN: register\n");

        if (cache_update(hd) < 0)
                return (RCM_FAILURE);

        /*
         * Need to register interest in all new resources
         * getting attached, so we get attach event notifications
         */
        if (!events_registered) {
                if (rcm_register_event(hd, RCM_RESOURCE_LINK_NEW, 0, NULL)
                    != RCM_SUCCESS) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: failed to register %s\n"),
                            RCM_RESOURCE_LINK_NEW);
                        return (RCM_FAILURE);
                } else {
                        rcm_log_message(RCM_DEBUG, "VLAN: registered %s\n",
                            RCM_RESOURCE_LINK_NEW);
                        events_registered++;
                }
        }

        return (RCM_SUCCESS);
}

/*
 * vlan_unregister() - Walk the cache, unregistering all the networks.
 */
static int
vlan_unregister(rcm_handle_t *hd)
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE1, "VLAN: unregister\n");

        /* Walk the cache, unregistering everything */
        (void) mutex_lock(&cache_lock);
        node = cache_head.vc_next;
        while (node != &cache_tail) {
                if (rcm_unregister_interest(hd, node->vc_resource, 0)
                    != RCM_SUCCESS) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: failed to unregister %s\n"),
                            node->vc_resource);
                        (void) mutex_unlock(&cache_lock);
                        return (RCM_FAILURE);
                }
                cache_remove(node);
                node_free(node);
                node = cache_head.vc_next;
        }
        (void) mutex_unlock(&cache_lock);

        /*
         * Unregister interest in all new resources
         */
        if (events_registered) {
                if (rcm_unregister_event(hd, RCM_RESOURCE_LINK_NEW, 0)
                    != RCM_SUCCESS) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: failed to unregister %s\n"),
                            RCM_RESOURCE_LINK_NEW);
                        return (RCM_FAILURE);
                } else {
                        rcm_log_message(RCM_DEBUG, "VLAN: unregistered %s\n",
                            RCM_RESOURCE_LINK_NEW);
                        events_registered--;
                }
        }

        return (RCM_SUCCESS);
}

/*
 * vlan_offline() - Offline VLANs on a specific node.
 */
static int
vlan_offline(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **errorp, rcm_info_t **info)
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE1, "VLAN: offline(%s)\n", rsrc);

        /* Lock the cache and lookup the resource */
        (void) mutex_lock(&cache_lock);
        node = cache_lookup(hd, rsrc, CACHE_REFRESH);
        if (node == NULL) {
                /* should not happen because the resource is registered. */
                vlan_log_err(DATALINK_INVALID_LINKID, errorp,
                    "unrecognized resource");
                (void) mutex_unlock(&cache_lock);
                return (RCM_SUCCESS);
        }

        /*
         * Inform consumers (IP interfaces) of associated VLANs to be offlined
         */
        if (vlan_consumer_offline(hd, node, errorp, flags, info) ==
            RCM_SUCCESS) {
                rcm_log_message(RCM_DEBUG,
                    "VLAN: consumers agreed on offline\n");
        } else {
                vlan_log_err(node->vc_linkid, errorp,
                    "consumers failed to offline");
                (void) mutex_unlock(&cache_lock);
                return (RCM_FAILURE);
        }

        /* Check if it's a query */
        if (flags & RCM_QUERY) {
                rcm_log_message(RCM_TRACE1,
                    "VLAN: offline query succeeded(%s)\n", rsrc);
                (void) mutex_unlock(&cache_lock);
                return (RCM_SUCCESS);
        }

        if (vlan_offline_vlan(node, VLAN_OFFLINED, CACHE_NODE_OFFLINED) !=
            RCM_SUCCESS) {
                vlan_online_vlan(node);
                vlan_log_err(node->vc_linkid, errorp, "offline failed");
                (void) mutex_unlock(&cache_lock);
                return (RCM_FAILURE);
        }

        rcm_log_message(RCM_TRACE1, "VLAN: Offline succeeded(%s)\n", rsrc);
        (void) mutex_unlock(&cache_lock);
        return (RCM_SUCCESS);
}

/*
 * vlan_undo_offline() - Undo offline of a previously offlined node.
 */
/*ARGSUSED*/
static int
vlan_undo_offline(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **errorp, rcm_info_t **info)
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE1, "VLAN: online(%s)\n", rsrc);

        (void) mutex_lock(&cache_lock);
        node = cache_lookup(hd, rsrc, CACHE_NO_REFRESH);
        if (node == NULL) {
                vlan_log_err(DATALINK_INVALID_LINKID, errorp, "no such link");
                (void) mutex_unlock(&cache_lock);
                errno = ENOENT;
                return (RCM_FAILURE);
        }

        /* Check if no attempt should be made to online the link here */
        if (!(node->vc_state & CACHE_NODE_OFFLINED)) {
                vlan_log_err(node->vc_linkid, errorp, "link not offlined");
                (void) mutex_unlock(&cache_lock);
                errno = ENOTSUP;
                return (RCM_SUCCESS);
        }

        vlan_online_vlan(node);

        /*
         * Inform IP interfaces on associated VLANs to be onlined
         */
        vlan_consumer_online(hd, node, errorp, flags, info);

        node->vc_state &= ~CACHE_NODE_OFFLINED;
        rcm_log_message(RCM_TRACE1, "VLAN: online succeeded(%s)\n", rsrc);
        (void) mutex_unlock(&cache_lock);
        return (RCM_SUCCESS);
}

static void
vlan_online_vlan(link_cache_t *node)
{
        dl_vlan_t *vlan;
        dladm_status_t status;
        char errmsg[DLADM_STRSIZE];

        /*
         * Try to bring on all offlined VLANs
         */
        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                if (!(vlan->dv_flags & VLAN_OFFLINED))
                        continue;

                if ((status = dladm_vlan_up(dld_handle, vlan->dv_vlanid)) !=
                    DLADM_STATUS_OK) {
                        /*
                         * Print a warning message and continue to online
                         * other VLANs.
                         */
                        rcm_log_message(RCM_WARNING,
                            _("VLAN: VLAN online failed (%u): %s\n"),
                            vlan->dv_vlanid, dladm_status2str(status, errmsg));
                } else {
                        vlan->dv_flags &= ~VLAN_OFFLINED;
                }
        }
}

static int
vlan_offline_vlan(link_cache_t *node, uint32_t flags, cache_node_state_t state)
{
        dl_vlan_t *vlan;
        dladm_status_t status;
        char errmsg[DLADM_STRSIZE];

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_offline_vlan (%s %u %u)\n",
            node->vc_resource, flags, state);

        /*
         * Try to delete all explicit created VLAN
         */
        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                if ((status = dladm_vlan_delete(dld_handle, vlan->dv_vlanid,
                    DLADM_OPT_ACTIVE)) != DLADM_STATUS_OK) {
                        rcm_log_message(RCM_WARNING,
                            _("VLAN: VLAN offline failed (%u): %s\n"),
                            vlan->dv_vlanid, dladm_status2str(status, errmsg));
                        return (RCM_FAILURE);
                } else {
                        rcm_log_message(RCM_TRACE1,
                            "VLAN: VLAN offline succeeded(%u)\n",
                            vlan->dv_vlanid);
                        vlan->dv_flags |= flags;
                }
        }

        node->vc_state |= state;
        return (RCM_SUCCESS);
}

/*
 * vlan_get_info() - Gather usage information for this resource.
 */
/*ARGSUSED*/
int
vlan_get_info(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **usagep, char **errorp, nvlist_t *props, rcm_info_t **info)
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE1, "VLAN: get_info(%s)\n", rsrc);

        (void) mutex_lock(&cache_lock);
        node = cache_lookup(hd, rsrc, CACHE_REFRESH);
        if (node == NULL) {
                rcm_log_message(RCM_INFO,
                    _("VLAN: get_info(%s) unrecognized resource\n"), rsrc);
                (void) mutex_unlock(&cache_lock);
                errno = ENOENT;
                return (RCM_FAILURE);
        }

        *usagep = vlan_usage(node);
        (void) mutex_unlock(&cache_lock);
        if (*usagep == NULL) {
                /* most likely malloc failure */
                rcm_log_message(RCM_ERROR,
                    _("VLAN: get_info(%s) malloc failure\n"), rsrc);
                (void) mutex_unlock(&cache_lock);
                errno = ENOMEM;
                return (RCM_FAILURE);
        }

        /* Set client/role properties */
        (void) nvlist_add_string(props, RCM_CLIENT_NAME, "VLAN");

        rcm_log_message(RCM_TRACE1, "VLAN: get_info(%s) info = %s\n",
            rsrc, *usagep);
        return (RCM_SUCCESS);
}

/*
 * vlan_suspend() - Nothing to do, always okay
 */
/*ARGSUSED*/
static int
vlan_suspend(rcm_handle_t *hd, char *rsrc, id_t id, timespec_t *interval,
    uint_t flags, char **errorp, rcm_info_t **info)
{
        rcm_log_message(RCM_TRACE1, "VLAN: suspend(%s)\n", rsrc);
        return (RCM_SUCCESS);
}

/*
 * vlan_resume() - Nothing to do, always okay
 */
/*ARGSUSED*/
static int
vlan_resume(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **errorp, rcm_info_t **info)
{
        rcm_log_message(RCM_TRACE1, "VLAN: resume(%s)\n", rsrc);
        return (RCM_SUCCESS);
}

/*
 * vlan_consumer_remove()
 *
 *      Notify VLAN consumers to remove cache.
 */
static int
vlan_consumer_remove(rcm_handle_t *hd, link_cache_t *node, uint_t flags,
    rcm_info_t **info)
{
        dl_vlan_t *vlan = NULL;
        char rsrc[RCM_LINK_RESOURCE_MAX];
        int ret = RCM_SUCCESS;

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_remove (%s)\n",
            node->vc_resource);

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {

                /*
                 * This will only be called when the offline operation
                 * succeeds, so the VLAN consumers must have been offlined
                 * at this point.
                 */
                assert(vlan->dv_flags & VLAN_CONSUMER_OFFLINED);

                (void) snprintf(rsrc, RCM_LINK_RESOURCE_MAX, "%s/%u",
                    RCM_LINK_PREFIX, vlan->dv_vlanid);

                ret = rcm_notify_remove(hd, rsrc, flags, info);
                if (ret != RCM_SUCCESS) {
                        rcm_log_message(RCM_WARNING,
                            _("VLAN: notify remove failed (%s)\n"), rsrc);
                        break;
                }
        }

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_remove done\n");
        return (ret);
}

/*
 * vlan_remove() - remove a resource from cache
 */
/*ARGSUSED*/
static int
vlan_remove(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **errorp, rcm_info_t **info)
{
        link_cache_t *node;
        int rv;

        rcm_log_message(RCM_TRACE1, "VLAN: remove(%s)\n", rsrc);

        (void) mutex_lock(&cache_lock);
        node = cache_lookup(hd, rsrc, CACHE_NO_REFRESH);
        if (node == NULL) {
                rcm_log_message(RCM_INFO,
                    _("VLAN: remove(%s) unrecognized resource\n"), rsrc);
                (void) mutex_unlock(&cache_lock);
                errno = ENOENT;
                return (RCM_FAILURE);
        }

        /* remove the cached entry for the resource */
        cache_remove(node);
        (void) mutex_unlock(&cache_lock);

        rv = vlan_consumer_remove(hd, node, flags, info);
        node_free(node);
        return (rv);
}

/*
 * vlan_notify_event - Project private implementation to receive new resource
 *                 events. It intercepts all new resource events. If the
 *                 new resource is a network resource, pass up a notify
 *                 for it too. The new resource need not be cached, since
 *                 it is done at register again.
 */
/*ARGSUSED*/
static int
vlan_notify_event(rcm_handle_t *hd, char *rsrc, id_t id, uint_t flags,
    char **errorp, nvlist_t *nvl, rcm_info_t **info)
{
        nvpair_t        *nvp = NULL;
        datalink_id_t   linkid;
        uint64_t        id64;
        int             rv = RCM_SUCCESS;

        rcm_log_message(RCM_TRACE1, "VLAN: notify_event(%s)\n", rsrc);

        if (strcmp(rsrc, RCM_RESOURCE_LINK_NEW) != 0) {
                vlan_log_err(DATALINK_INVALID_LINKID, errorp,
                    "unrecognized event");
                errno = EINVAL;
                return (RCM_FAILURE);
        }

        /* Update cache to reflect latest VLANs */
        if (cache_update(hd) < 0) {
                vlan_log_err(DATALINK_INVALID_LINKID, errorp,
                    "private Cache update failed");
                return (RCM_FAILURE);
        }

        /*
         * Try best to recover all configuration.
         */
        rcm_log_message(RCM_DEBUG, "VLAN: process_nvlist\n");
        while ((nvp = nvlist_next_nvpair(nvl, nvp)) != NULL) {
                if (strcmp(nvpair_name(nvp), RCM_NV_LINKID) != 0)
                        continue;

                if (nvpair_value_uint64(nvp, &id64) != 0) {
                        vlan_log_err(DATALINK_INVALID_LINKID, errorp,
                            "cannot get linkid");
                        rv = RCM_FAILURE;
                        continue;
                }

                linkid = (datalink_id_t)id64;
                if (vlan_configure(hd, linkid) != 0) {
                        vlan_log_err(linkid, errorp, "configuring failed");
                        rv = RCM_FAILURE;
                        continue;
                }

                /* Notify all VLAN consumers */
                if (vlan_consumer_notify(hd, linkid, errorp, flags,
                    info) != 0) {
                        vlan_log_err(linkid, errorp, "consumer notify failed");
                        rv = RCM_FAILURE;
                }
        }

        rcm_log_message(RCM_TRACE1,
            "VLAN: notify_event: link configuration complete\n");
        return (rv);
}

/*
 * vlan_usage - Determine the usage of a link.
 *          The returned buffer is owned by caller, and the caller
 *          must free it up when done.
 */
static char *
vlan_usage(link_cache_t *node)
{
        dl_vlan_t *vlan;
        int nvlan;
        char *buf;
        const char *fmt;
        char *sep;
        char errmsg[DLADM_STRSIZE];
        char name[MAXLINKNAMELEN];
        dladm_status_t status;
        size_t bufsz;

        rcm_log_message(RCM_TRACE2, "VLAN: usage(%s)\n", node->vc_resource);

        assert(MUTEX_HELD(&cache_lock));
        if ((status = dladm_datalink_id2info(dld_handle, node->vc_linkid, NULL,
            NULL, NULL, name, sizeof (name))) != DLADM_STATUS_OK) {
                rcm_log_message(RCM_ERROR,
                    _("VLAN: usage(%s) get link name failure(%s)\n"),
                    node->vc_resource, dladm_status2str(status, errmsg));
                return (NULL);
        }

        if (node->vc_state & CACHE_NODE_OFFLINED)
                fmt = _("%1$s offlined");
        else
                fmt = _("%1$s VLANs: ");

        /* TRANSLATION_NOTE: separator used between VLAN linkids */
        sep = _(", ");

        nvlan = 0;
        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next)
                nvlan++;

        /* space for VLANs and separators, plus message */
        bufsz = nvlan * (MAXLINKNAMELEN + strlen(sep)) +
            strlen(fmt) + MAXLINKNAMELEN + 1;
        if ((buf = malloc(bufsz)) == NULL) {
                rcm_log_message(RCM_ERROR,
                    _("VLAN: usage(%s) malloc failure(%s)\n"),
                    node->vc_resource, strerror(errno));
                return (NULL);
        }
        (void) snprintf(buf, bufsz, fmt, name);

        if (node->vc_state & CACHE_NODE_OFFLINED) {
                /* Nothing else to do */
                rcm_log_message(RCM_TRACE2, "VLAN: usage (%s) info = %s\n",
                    node->vc_resource, buf);
                return (buf);
        }

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                rcm_log_message(RCM_DEBUG, "VLAN:= %u\n", vlan->dv_vlanid);

                if ((status = dladm_datalink_id2info(dld_handle,
                    vlan->dv_vlanid, NULL, NULL, NULL, name,
                    sizeof (name))) != DLADM_STATUS_OK) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: usage(%s) get vlan %u name failure(%s)\n"),
                            node->vc_resource, vlan->dv_vlanid,
                            dladm_status2str(status, errmsg));
                        free(buf);
                        return (NULL);
                }

                (void) strlcat(buf, name, bufsz);
                if (vlan->dv_next != NULL)
                        (void) strlcat(buf, sep, bufsz);
        }

        rcm_log_message(RCM_TRACE2, "VLAN: usage (%s) info = %s\n",
            node->vc_resource, buf);

        return (buf);
}

/*
 * Cache management routines, all cache management functions should be
 * be called with cache_lock held.
 */

/*
 * cache_lookup() - Get a cache node for a resource.
 *                Call with cache lock held.
 *
 * This ensures that the cache is consistent with the system state and
 * returns a pointer to the cache element corresponding to the resource.
 */
static link_cache_t *
cache_lookup(rcm_handle_t *hd, char *rsrc, char options)
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE2, "VLAN: cache lookup(%s)\n", rsrc);

        assert(MUTEX_HELD(&cache_lock));
        if (options & CACHE_REFRESH) {
                /* drop lock since update locks cache again */
                (void) mutex_unlock(&cache_lock);
                (void) cache_update(hd);
                (void) mutex_lock(&cache_lock);
        }

        node = cache_head.vc_next;
        for (; node != &cache_tail; node = node->vc_next) {
                if (strcmp(rsrc, node->vc_resource) == 0) {
                        rcm_log_message(RCM_TRACE2,
                            "VLAN: cache lookup succeeded(%s)\n", rsrc);
                        return (node);
                }
        }
        return (NULL);
}

/*
 * node_free - Free a node from the cache
 */
static void
node_free(link_cache_t *node)
{
        dl_vlan_t *vlan, *next;

        if (node != NULL) {
                free(node->vc_resource);

                /* free the VLAN list */
                for (vlan = node->vc_vlan; vlan != NULL; vlan = next) {
                        next = vlan->dv_next;
                        free(vlan);
                }
                free(node);
        }
}

/*
 * cache_insert - Insert a resource node in cache
 */
static void
cache_insert(link_cache_t *node)
{
        assert(MUTEX_HELD(&cache_lock));

        /* insert at the head for best performance */
        node->vc_next = cache_head.vc_next;
        node->vc_prev = &cache_head;

        node->vc_next->vc_prev = node;
        node->vc_prev->vc_next = node;
}

/*
 * cache_remove() - Remove a resource node from cache.
 */
static void
cache_remove(link_cache_t *node)
{
        assert(MUTEX_HELD(&cache_lock));
        node->vc_next->vc_prev = node->vc_prev;
        node->vc_prev->vc_next = node->vc_next;
        node->vc_next = NULL;
        node->vc_prev = NULL;
}

typedef struct vlan_update_arg_s {
        rcm_handle_t    *hd;
        int             retval;
} vlan_update_arg_t;

/*
 * vlan_update() - Update physical interface properties
 */
static int
vlan_update(dladm_handle_t handle, datalink_id_t vlanid, void *arg)
{
        vlan_update_arg_t *vlan_update_argp = arg;
        rcm_handle_t *hd = vlan_update_argp->hd;
        link_cache_t *node;
        dl_vlan_t *vlan;
        char *rsrc;
        dladm_vlan_attr_t vlan_attr;
        dladm_status_t status;
        char errmsg[DLADM_STRSIZE];
        boolean_t newnode = B_FALSE;
        int ret = -1;

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_update(%u)\n", vlanid);

        assert(MUTEX_HELD(&cache_lock));
        status = dladm_vlan_info(handle, vlanid, &vlan_attr, DLADM_OPT_ACTIVE);
        if (status != DLADM_STATUS_OK) {
                rcm_log_message(RCM_TRACE1,
                    "VLAN: vlan_update() cannot get vlan information for "
                    "%u(%s)\n", vlanid, dladm_status2str(status, errmsg));
                return (DLADM_WALK_CONTINUE);
        }

        rsrc = malloc(RCM_LINK_RESOURCE_MAX);
        if (rsrc == NULL) {
                rcm_log_message(RCM_ERROR, _("VLAN: malloc error(%s): %u\n"),
                    strerror(errno), vlanid);
                goto done;
        }

        (void) snprintf(rsrc, RCM_LINK_RESOURCE_MAX, "%s/%u",
            RCM_LINK_PREFIX, vlan_attr.dv_linkid);

        node = cache_lookup(hd, rsrc, CACHE_NO_REFRESH);
        if (node != NULL) {
                rcm_log_message(RCM_DEBUG,
                    "VLAN: %s already registered (vlanid:%d)\n",
                    rsrc, vlan_attr.dv_vid);
                free(rsrc);
        } else {
                rcm_log_message(RCM_DEBUG,
                    "VLAN: %s is a new resource (vlanid:%d)\n",
                    rsrc, vlan_attr.dv_vid);
                if ((node = calloc(1, sizeof (link_cache_t))) == NULL) {
                        free(rsrc);
                        rcm_log_message(RCM_ERROR, _("VLAN: calloc: %s\n"),
                            strerror(errno));
                        goto done;
                }

                node->vc_resource = rsrc;
                node->vc_vlan = NULL;
                node->vc_linkid = vlan_attr.dv_linkid;
                node->vc_state |= CACHE_NODE_NEW;
                newnode = B_TRUE;
        }

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                if (vlan->dv_vlanid == vlanid) {
                        vlan->dv_flags &= ~VLAN_STALE;
                        break;
                }
        }

        if (vlan == NULL) {
                if ((vlan = calloc(1, sizeof (dl_vlan_t))) == NULL) {
                        rcm_log_message(RCM_ERROR, _("VLAN: malloc: %s\n"),
                            strerror(errno));
                        if (newnode) {
                                free(rsrc);
                                free(node);
                        }
                        goto done;
                }
                vlan->dv_vlanid = vlanid;
                vlan->dv_next = node->vc_vlan;
                vlan->dv_prev = NULL;
                if (node->vc_vlan != NULL)
                        node->vc_vlan->dv_prev = vlan;
                node->vc_vlan = vlan;
        }

        node->vc_state &= ~CACHE_NODE_STALE;

        if (newnode)
                cache_insert(node);

        rcm_log_message(RCM_TRACE3, "VLAN: vlan_update: succeeded(%u)\n",
            vlanid);
        ret = 0;
done:
        vlan_update_argp->retval = ret;
        return (ret == 0 ? DLADM_WALK_CONTINUE : DLADM_WALK_TERMINATE);
}

/*
 * vlan_update_all() - Determine all VLAN links in the system
 */
static int
vlan_update_all(rcm_handle_t *hd)
{
        vlan_update_arg_t arg = {NULL, 0};

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_update_all\n");

        assert(MUTEX_HELD(&cache_lock));
        arg.hd = hd;
        (void) dladm_walk_datalink_id(vlan_update, dld_handle, &arg,
            DATALINK_CLASS_VLAN, DATALINK_ANY_MEDIATYPE, DLADM_OPT_ACTIVE);
        return (arg.retval);
}

/*
 * cache_update() - Update cache with latest interface info
 */
static int
cache_update(rcm_handle_t *hd)
{
        link_cache_t *node, *nnode;
        dl_vlan_t *vlan;
        int rv;

        rcm_log_message(RCM_TRACE2, "VLAN: cache_update\n");

        (void) mutex_lock(&cache_lock);

        /* first we walk the entire cache, marking each entry stale */
        node = cache_head.vc_next;
        for (; node != &cache_tail; node = node->vc_next) {
                node->vc_state |= CACHE_NODE_STALE;
                for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next)
                        vlan->dv_flags |= VLAN_STALE;
        }

        rv = vlan_update_all(hd);

        /*
         * Continue to delete all stale nodes from the cache even
         * vlan_update_all() failed. Unregister link that are not offlined
         * and still in cache
         */
        for (node = cache_head.vc_next; node != &cache_tail; node = nnode) {
                dl_vlan_t *vlan, *next;

                for (vlan = node->vc_vlan; vlan != NULL; vlan = next) {
                        next = vlan->dv_next;

                        /* clear stale VLANs */
                        if (vlan->dv_flags & VLAN_STALE) {
                                if (vlan->dv_prev != NULL)
                                        vlan->dv_prev->dv_next = next;
                                else
                                        node->vc_vlan = next;

                                if (next != NULL)
                                        next->dv_prev = vlan->dv_prev;
                                free(vlan);
                        }
                }

                nnode = node->vc_next;
                if (node->vc_state & CACHE_NODE_STALE) {
                        (void) rcm_unregister_interest(hd, node->vc_resource,
                            0);
                        rcm_log_message(RCM_DEBUG, "VLAN: unregistered %s\n",
                            node->vc_resource);
                        assert(node->vc_vlan == NULL);
                        cache_remove(node);
                        node_free(node);
                        continue;
                }

                if (!(node->vc_state & CACHE_NODE_NEW))
                        continue;

                if (rcm_register_interest(hd, node->vc_resource, 0, NULL) !=
                    RCM_SUCCESS) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: failed to register %s\n"),
                            node->vc_resource);
                        rv = -1;
                } else {
                        rcm_log_message(RCM_DEBUG, "VLAN: registered %s\n",
                            node->vc_resource);
                        node->vc_state &= ~CACHE_NODE_NEW;
                }
        }

        (void) mutex_unlock(&cache_lock);
        return (rv);
}

/*
 * cache_free() - Empty the cache
 */
static void
cache_free()
{
        link_cache_t *node;

        rcm_log_message(RCM_TRACE2, "VLAN: cache_free\n");

        (void) mutex_lock(&cache_lock);
        node = cache_head.vc_next;
        while (node != &cache_tail) {
                cache_remove(node);
                node_free(node);
                node = cache_head.vc_next;
        }
        (void) mutex_unlock(&cache_lock);
}

/*
 * vlan_log_err() - RCM error log wrapper
 */
static void
vlan_log_err(datalink_id_t linkid, char **errorp, char *errmsg)
{
        char link[MAXLINKNAMELEN];
        char errstr[DLADM_STRSIZE];
        dladm_status_t status;
        int len;
        const char *errfmt;
        char *error;

        link[0] = '\0';
        if (linkid != DATALINK_INVALID_LINKID) {
                char rsrc[RCM_LINK_RESOURCE_MAX];

                (void) snprintf(rsrc, sizeof (rsrc), "%s/%u",
                    RCM_LINK_PREFIX, linkid);

                rcm_log_message(RCM_ERROR, _("VLAN: %s(%s)\n"), errmsg, rsrc);
                if ((status = dladm_datalink_id2info(dld_handle, linkid, NULL,
                    NULL, NULL, link, sizeof (link))) != DLADM_STATUS_OK) {
                        rcm_log_message(RCM_WARNING,
                            _("VLAN: cannot get link name for (%s) %s\n"),
                            rsrc, dladm_status2str(status, errstr));
                }
        } else {
                rcm_log_message(RCM_ERROR, _("VLAN: %s\n"), errmsg);
        }

        errfmt = strlen(link) > 0 ? _("VLAN: %s(%s)") : _("VLAN: %s");
        len = strlen(errfmt) + strlen(errmsg) + MAXLINKNAMELEN + 1;
        if ((error = malloc(len)) != NULL) {
                if (strlen(link) > 0)
                        (void) snprintf(error, len, errfmt, errmsg, link);
                else
                        (void) snprintf(error, len, errfmt, errmsg);
        }

        if (errorp != NULL)
                *errorp = error;
}

/*
 * vlan_consumer_online()
 *
 *      Notify online to VLAN consumers.
 */
/* ARGSUSED */
static void
vlan_consumer_online(rcm_handle_t *hd, link_cache_t *node, char **errorp,
    uint_t flags, rcm_info_t **info)
{
        dl_vlan_t *vlan;
        char rsrc[RCM_LINK_RESOURCE_MAX];

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_online (%s)\n",
            node->vc_resource);

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                if (!(vlan->dv_flags & VLAN_CONSUMER_OFFLINED))
                        continue;

                (void) snprintf(rsrc, RCM_LINK_RESOURCE_MAX, "%s/%u",
                    RCM_LINK_PREFIX, vlan->dv_vlanid);

                if (rcm_notify_online(hd, rsrc, flags, info) == RCM_SUCCESS)
                        vlan->dv_flags &= ~VLAN_CONSUMER_OFFLINED;
        }

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_online done\n");
}

/*
 * vlan_consumer_offline()
 *
 *      Offline VLAN consumers.
 */
static int
vlan_consumer_offline(rcm_handle_t *hd, link_cache_t *node, char **errorp,
    uint_t flags, rcm_info_t **info)
{
        dl_vlan_t *vlan;
        char rsrc[RCM_LINK_RESOURCE_MAX];
        int ret = RCM_SUCCESS;

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_offline (%s)\n",
            node->vc_resource);

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                (void) snprintf(rsrc, RCM_LINK_RESOURCE_MAX, "%s/%u",
                    RCM_LINK_PREFIX, vlan->dv_vlanid);

                ret = rcm_request_offline(hd, rsrc, flags, info);
                if (ret != RCM_SUCCESS)
                        break;

                vlan->dv_flags |= VLAN_CONSUMER_OFFLINED;
        }

        if (vlan != NULL)
                vlan_consumer_online(hd, node, errorp, flags, info);

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_offline done\n");
        return (ret);
}

/*
 * Send RCM_RESOURCE_LINK_NEW events to other modules about new VLANs.
 * Return 0 on success, -1 on failure.
 */
static int
vlan_notify_new_vlan(rcm_handle_t *hd, char *rsrc)
{
        link_cache_t *node;
        dl_vlan_t *vlan;
        nvlist_t *nvl = NULL;
        uint64_t id;
        int ret = -1;

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_notify_new_vlan (%s)\n", rsrc);

        (void) mutex_lock(&cache_lock);
        if ((node = cache_lookup(hd, rsrc, CACHE_REFRESH)) == NULL) {
                (void) mutex_unlock(&cache_lock);
                return (0);
        }

        if (nvlist_alloc(&nvl, 0, 0) != 0) {
                (void) mutex_unlock(&cache_lock);
                rcm_log_message(RCM_WARNING,
                    _("VLAN: failed to allocate nvlist\n"));
                goto done;
        }

        for (vlan = node->vc_vlan; vlan != NULL; vlan = vlan->dv_next) {
                rcm_log_message(RCM_TRACE2,
                    "VLAN: vlan_notify_new_vlan add (%u)\n",
                    vlan->dv_vlanid);

                id = vlan->dv_vlanid;
                if (nvlist_add_uint64(nvl, RCM_NV_LINKID, id) != 0) {
                        rcm_log_message(RCM_ERROR,
                            _("VLAN: failed to construct nvlist\n"));
                        (void) mutex_unlock(&cache_lock);
                        goto done;
                }
        }
        (void) mutex_unlock(&cache_lock);

        if (rcm_notify_event(hd, RCM_RESOURCE_LINK_NEW, 0, nvl, NULL) !=
            RCM_SUCCESS) {
                rcm_log_message(RCM_ERROR,
                    _("VLAN: failed to notify %s event for %s\n"),
                    RCM_RESOURCE_LINK_NEW, node->vc_resource);
                goto done;
        }

        ret = 0;
done:
        nvlist_free(nvl);
        return (ret);
}

/*
 * vlan_consumer_notify() - Notify consumers of VLANs coming back online.
 */
static int
vlan_consumer_notify(rcm_handle_t *hd, datalink_id_t linkid, char **errorp,
    uint_t flags, rcm_info_t **info)
{
        char rsrc[RCM_LINK_RESOURCE_MAX];
        link_cache_t *node;

        /* Check for the interface in the cache */
        (void) snprintf(rsrc, RCM_LINK_RESOURCE_MAX, "%s/%u", RCM_LINK_PREFIX,
            linkid);

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_notify(%s)\n", rsrc);

        /*
         * Inform IP consumers of the new link.
         */
        if (vlan_notify_new_vlan(hd, rsrc) != 0) {
                (void) mutex_lock(&cache_lock);
                if ((node = cache_lookup(hd, rsrc, CACHE_NO_REFRESH)) != NULL) {
                        (void) vlan_offline_vlan(node, VLAN_STALE,
                            CACHE_NODE_STALE);
                }
                (void) mutex_unlock(&cache_lock);
                rcm_log_message(RCM_TRACE2,
                    "VLAN: vlan_notify_new_vlan failed(%s)\n", rsrc);
                return (-1);
        }

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_consumer_notify succeeded\n");
        return (0);
}

typedef struct vlan_up_arg_s {
        datalink_id_t   linkid;
        int             retval;
} vlan_up_arg_t;

static int
vlan_up(dladm_handle_t handle, datalink_id_t vlanid, void *arg)
{
        vlan_up_arg_t *vlan_up_argp = arg;
        dladm_status_t status;
        dladm_vlan_attr_t vlan_attr;
        char errmsg[DLADM_STRSIZE];

        status = dladm_vlan_info(handle, vlanid, &vlan_attr, DLADM_OPT_PERSIST);
        if (status != DLADM_STATUS_OK) {
                rcm_log_message(RCM_TRACE1,
                    "VLAN: vlan_up(): cannot get information for VLAN %u "
                    "(%s)\n", vlanid, dladm_status2str(status, errmsg));
                return (DLADM_WALK_CONTINUE);
        }

        if (vlan_attr.dv_linkid != vlan_up_argp->linkid)
                return (DLADM_WALK_CONTINUE);

        rcm_log_message(RCM_TRACE3, "VLAN: vlan_up(%u)\n", vlanid);
        if ((status = dladm_vlan_up(handle, vlanid)) == DLADM_STATUS_OK)
                return (DLADM_WALK_CONTINUE);

        /*
         * Prompt the warning message and continue to UP other VLANs.
         */
        rcm_log_message(RCM_WARNING,
            _("VLAN: VLAN up failed (%u): %s\n"),
            vlanid, dladm_status2str(status, errmsg));

        vlan_up_argp->retval = -1;
        return (DLADM_WALK_CONTINUE);
}

/*
 * vlan_configure() - Configure VLANs over a physical link after it attaches
 */
static int
vlan_configure(rcm_handle_t *hd, datalink_id_t linkid)
{
        char rsrc[RCM_LINK_RESOURCE_MAX];
        link_cache_t *node;
        vlan_up_arg_t arg = {DATALINK_INVALID_LINKID, 0};

        /* Check for the VLANs in the cache */
        (void) snprintf(rsrc, sizeof (rsrc), "%s/%u", RCM_LINK_PREFIX, linkid);

        rcm_log_message(RCM_TRACE2, "VLAN: vlan_configure(%s)\n", rsrc);

        /* Check if the link is new or was previously offlined */
        (void) mutex_lock(&cache_lock);
        if (((node = cache_lookup(hd, rsrc, CACHE_REFRESH)) != NULL) &&
            (!(node->vc_state & CACHE_NODE_OFFLINED))) {
                rcm_log_message(RCM_TRACE2,
                    "VLAN: Skipping configured interface(%s)\n", rsrc);
                (void) mutex_unlock(&cache_lock);
                return (0);
        }
        (void) mutex_unlock(&cache_lock);

        arg.linkid = linkid;
        (void) dladm_walk_datalink_id(vlan_up, dld_handle, &arg,
            DATALINK_CLASS_VLAN, DATALINK_ANY_MEDIATYPE, DLADM_OPT_PERSIST);

        if (arg.retval == 0) {
                rcm_log_message(RCM_TRACE2,
                    "VLAN: vlan_configure succeeded(%s)\n", rsrc);
        }
        return (arg.retval);
}